This invention relates to a device for shooting bullets by pressure medium for use in a toy gun, which is adapted to shoot bullets in succession by making use of a pressure medium, e.g., carbonic acid gas, or propane or liquefied petroleum gas, etc.
As a conventional implementation, the inventor has set forth a shooting device in application Ser. No. 61-128687, filed June 3, 1986, now Pat. No. 62-288499, published Dec. 15, 1987 Japan.
Namely, FIG. 2 set forth herein is the same as FIG. 7 illustrated in said Japanese application, but shown with different reference characters. The device shown by FIG. 2 herein is a device 3 for shooting a bullet 2 by a pressure medium 1 for use in a toy gun comprises an outer tubular member 5 having a bullet introduction opening 4, a piston member 6 fitted into the outer tubular member 5 and reciprocating in response to changes in the pressure medium 1, a weight 8 associated with a needle valve 7 so as to be in engagement with the piston member 6 and out of engagement therewith and biased by a spring member 13 so as to strike against the needle valve 7. A packing member 9 is fitted into the outer tubular member 5 and adapted to receive a bullet 2 when opening 4 is opened by movement of end 6a to the right. The bullet, when received by packing member 9, is in a condition to be fired when the bullet introduction opening 4 is closed by the tip portion 6a of the piston member 6.
With the above-mentioned structure, however, the pressure medium 1 freely flows in from a gas introduction hole 10 formed in the rear wall of the outer tubular member 5. Thus, the pressure medium 1 always will be delivered to the backward side of a chamber accommodating section 11 of the outer tubular member 5 after the bullet 2 has been shot, as shown in the drawing.
Accordingly, if a setting is not made such that a time period during which the needle valve 7 is opened is sufficient so as to permit the returning process of the piston member 6, there will occur a situation such that the piston member 6 cannot be completely returned beyond the bullet introduction opening initial position by the biasing force of a first spring member 12.
For example, in a case where the spring force of a third spring member 13 is weak and the weight 8 is light, the needle valve 7 cannot be opened, or only for a time such as several one hundredths of a second, even in the presence of the collision of the weight 8. Accordingly, the piston member 6 fails to return to the bullet introduction open position during such a short period. As a result, the needle valve 7 is closed by the spring force of the second spring member 14 wound onto the back end portion of the needle valve 7 in the course of its return. Thus, the internal pressure of the chamber accommodating section 11 is raised by the pressure medium 1, which continues to flow from a gas cylinder 16 into the outer tubular member 5 through a supply hose 15. As a result, the piston member 6 begins advancing for a second time in its course of return.
At this time, the elastic or resilient weight hook arm 17 provided at the piston member 6 is out of engagement with the weight 8. In a short time, approximately at the time when the internal pressure of the outer tubular member 5 and the gas pressure of the pressure medium 1 flowing thereinto balance with each other, all movement of the respective members is stopped. This results in the drawback that a situation is brought about such that the second bullet and those subsequent thereto cannot be continuously shot, although the first bullet has been shot.